Ash Residue from Droplets of Organic Coal–Water Fuels Burned at Different Oxidant Temperatures

Abstract—The ash residue formed in the combustion of individual droplets (initial radius 0.5–2.0 mm) of organic coal–water fuels at different oxidizing-agent temperatures in an oxidant (hot-air) flux is studied experimentally. The main components of the fuel suspensions are as follows: coal filter cake; spent motor, transformer, and turbine oil; water; and a specialized plasticizer (wetting agent). The temperature and speed of the plasticizer vary in the ranges 600–1100 K and 0.5–5.0 m/s, corresponding to moderate- and low-temperature combustion (relative to traditional power-industry conditions). The mass of unburnt fuel components of the ash residue is determined. The elementary composition of the ash residue is analyzed. The influence of the oxidant temperature and the fuel components on the characteristics of the ash residue after combustion is studied.